Integrating data-based modeling and nonlinear control tools for batch process control

A data-based multimodel approach is developed in this work for modeling batch systems in which multiple local linear models are identified using latent variable regression and combined using an appropriate weighting function that arises from fuzzy c-means clustering. The resulting model is used to generate empirical reverse-time reachability regions (RTRRs) (defined as the set of states from where the data-based model can be driven inside a desired end-point neighborhood of the system), which are subsequently incorporated in a predictive control design. Simulation results of a fed-batch reactor system under proportional-integral (PI) control and the proposed RTRR-based design demonstrate the superior performance of the RTRR-based design in both a fault-free and faulty environment. The data-based modeling methodology is then applied on a nylon-6,6 batch polymerization process to design a trajectory tracking predictive controller. Closed-loop simulation results illustrate the superior tracking performance of the proposed predictive controller over PI control. (C) 2011 American Institute of Chemical Engineers AIChE J, 2012